Drawing frame sliver controlling enclosure



Nov. 4, 1958 Filed Nov. 7. 1957 United States Patent DRAWING FRAMESLIVER CONTROLLING ENCLOSURE Paul B. West, Kennebunk, Maine, assignor toSam- Lowell Shops, Boston, Mass., a corporation of Maine This inventionrelates to drawing frame calendering mechanisms and more particularly toa novel sliver controlling enclosure for a web of sliver from the nip ofthe drafting element output rolls of a drawing frame to the nip of therolls of the calendering mechanism thereof.

As is well understood by those skilled in this art, the sliver deliveredby a drawing frame from the nip of the last pair of rolls thereof mustbe moved for a distance of several inches to the nip of a calenderingmechanism which forms the input to the coiler portion or other take-upmechanism of the frame, such coiler portion disposing the sliver in thecustomary coiled formationin a-roving can and so providing a take-uppackage. During such movement, however, the untwisted sliver tends to beopened up with the individual cotton fibers or the like being spreadoutwardly and released from the body of the sliver, principally becauseof the action of the conventional trumpet in squeezing air out of'thesliver as the sliver enters it, but also because of the generation ofstatic electricity and the effect of the slivers movement through theair. In fact, in the case of modern high speed drawing frames, the speedof operation can readily be made great enough to cause the release ofindividual fibers from the body of the sliver in sufficient quantity sothat the output end of such a frame resembles a miniature snowstorm,with considerable loss of fiber. As a result, the practical speed ofoperation of such frames is limited by the loss of fiber which can betolerated rather than by the possible machine speed, and such operationis uneconomical. Furthermore, in addition to fiber loss, the sliver isinvariably damaged to some extent, so that yarn and cloth subsequentlymanufactured therefrom is of inferior quality, and again, such damageincreases as frame speed is increased.

Accordingly, it is an object of the present invention to provide a novelsliver supporting enclosure extending from adjacent the output rolls ofa drawing frame to the trumpet adjacent the calender rolls thereofeffective to permit the moving of a web of sliver from the nip of theoutput rolls of a drawing frame to the nip of the calendering mechanismthereof so that such sliver may be moved at the high speeds of whichmodern drawing frames are capable with greatly reduced and entirelytolerable fiber loss, tests with the apparatus of the inventionhavingindicated that fiber loss is almost completely eliminated, and thequality of the sliver is much improved. In more detail, the invention isbased on the principle of providing an enclosure whereby air squeezedout of the sliver by reason of the slivers entry into the trumpet isreturned in a direction countercurrent to the direction of movement ofthe sliver so that it can be absorbed into thesliver as the sliver isexpanding upon passing from the nip of the drawing frame output rolls,the .air stream being kept away from the sliver except in the regionadjacent the output rolls to avoid large relative'velocities between thesliver and the countercurrent air stream. i

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For the purpose of more fully explaining the various objects andfeatures of the invention, reference is now made to the followingdescription of a preferred embodiment of the invention, together withthe accompanying drawings, wherein:

Fig. 1 is an elevation of a portion of a drawing frame with the slivercontrolling enclosure of the invention thereon;

Fig. 2 is a plan of the sliver controlling enclosure of Fig. 1;

Fig. 3 is a side cross section of the enclosure of Fig. 2 taken on theline 3-3 thereof; and

Figs. 4 and 5 are cross sections taken on the lines 4-4 and 55 of Fig.3.

Referring to the drawings, the novel sliver controlling enclosure of theinvention is in the shape of a generally flat bottomed horn with flaringsides pivotally mounted on the drawing frame roll stand D, saidenclosure having its mouth opening adjacent the nip of the drawing frameoutput rolls R and its throat opening adjacent the calendering rolls Cand in sealing contact with the face of trumpet T above such latterrolls. The trumpet T in effect forms a continuation of the horn throatso that sliver S is moved from output rolls R to calendering rolls Calong the generally fiat bottom of the enclosure, with the enclosureproviding control of sliver movement as well as control of the aircurrents adjacent the sliver S.

Such air currents are affected as pointed out above, by the action ofthe output rolls R and trumpet T in compressing the sliver, since suchcompressing expels air from the sliver. Furthermore,-the resiliency ofthe sliver causes reabsorption of air when freed from the nip of saidrolls, so that air is being drawn into the sliver immediately followingits release from output rolls R and is being expressed from the sliverby trumpet T immediately preceding calendering rolls C. Accordingly, acertain amount of air is continuously being conveyed from the trumpet Tto the output rolls R and, with the enclosure of the invention, such airalmost in its entirety will be continuously returned for absorption intothe sliver. However, since such returning air must move countercurrentto the direction of motion of the sliver, it is important that airvelocities at the surface of the sliver be controlled to a reasonablylow value. This has been achieved in the enclosure of the presentinvention by providing an air passageway of sufiicient cross-sectionaldimension and spaced from the sliver S, such passageway taking the formof an upwardly extending enlargement or bulge in the otherwise flatupper surface of the horn in the throat region of the horn so that thetotal crosssectional area of the throat portion of the horn whereincountercurrent flow occurs is no less than about half that adjacent themouth of the horn wherein absorption is occurring. Such unique hornshape accomplishes return of the air expressed from the sliver withoutsubstantial disturbance of the sliver even at sliver speeds heretoforeconsidered impractically high.

The preferred embodiment of the horn structure of the invention, asshown in detail in Figs. 2 through 5, includes a generally fiat sheetmetal bottom or floor portion 10 and a top or cover portion 20. Saidfioor portion 10 has upwardly and inwardly turned flaring sides 12, thetransversely extending mouth forming lower edge 14 at the forward end ofsaid floor portion being pivotally mounted for upwardly swingingmovement about transverse pivot shaft 16. Preferably, the floor portionnear forward edge 14 is turned downward somewhat to facilitate entry ofsliver. The rear edge 18 of said floor portion 10 normally rests on thefiat upper face of trumpet T in a position .to provide a smooth lead forsliver S entering said trumpet and to effectively seal the enclosureagainst the entry of air between such edge and trumpet face. Due to thestatic electricity-generating characteristics of moving sliver ofcotton, wool or synthetic fiber, it is important that at least bottomportion have an interior surface \in contact with saidesliver ofnon-static. electricity generating material." The use: of .a conductive'materiaL-such as sheet metal --having; a

good electricalconnection to the drawing frame D, servesthis purposewell, although plastic materialsrmayv also be usedwith appropriatesurfacetreatment. The cover portion: 20"is also generally flat with an.upturned for-' ward edge 22 to facilitate entry of the sliver S into thenarrow rectangularmouth opening of the enclosure, .and yet to preventfree air communication insofar as pos-i sible without. interfering with:such entryn A. downturned rear edge 24 is also providedwhichzledgeextends beyond. floor portion rear-.iedgelli around theremainder ofthe periphery of trumpet T and generally coinciding'with itsopening for smooth sliver lead. .Preferably, a flange 26is:providedfaround the sbottom: of said edget24: to aid in'sealing.Flanges :28 are alsoprovided. along the flared :sides of cover portion20 to rest on and overlie the inwardly turned sides 12 .of bottomportion 20 to provide an effective seal along the sides of the entireenclosure.-

In accordance. with theabove recited principles of the linventiongabulge 30 is provided-on the cover portion 20. in the region of thethroat so that a passageway is provided for the returning air clear ofthe sliver surface; Such bulge begins in a smooth transition from therounded rear edge'24 of the cover portion and extends upwardly and alongthe relatively narrow throat portion of the enclosure, it being ofdecreasing height beyond said narrow throat portion until it mergessmoothly into the generally flat upper surface of the cover portion 20about two thirds of the distance from trumpet T to the forward edge ofthe enclosure. As can be seen particularly clearly in Figs. 3, 4 and 5,the bulge 30 provides an aerodynamically clean passageway for the airexpressed from the sliver at the trumpet T, in that such passagewaymerges smoothly both with trumpet T and into the relatively wide flatcover adjacent the mouth of the enclousre wherein air is continuouslybeing absorbed into the sliver S. Furthermore, such bulge in the regionof the relatively narrow throat portion of the enclosure provides analmost semi-circular cross-sectional configuration (Fig. 4) of muchgreater size thanis needed for the movement of the sliver S alone sothat an air passageway 32 of substantial area free of sliver can beprovided so that'air velocities adjacent the sliver surface areeifectively reduced.

Due tothe'unusual shape of cover 20, as Well as to the desirability of'being able to observe the sliver, it is preferred-that said cover 20 beof a clear plastic material, such as a vinyl, acrylic or styreneplastic, which can be readily formed as required, although metal couldbe'used' as well. With plastic, it is also preferable to treat theinterior surfaces, so that they do not generate static electricity,although it is less important than it is with the bottomsurface sincesliver does not normally contact the surfaces'of cover 20.

In operation, the sliver S passes from the nip .of the drawing frameoutput rolls R along the floor of the horn.- shaped enclosure of theinvention and through the trumpet T 'asmoved by calender rolls C. Sincethe enclosure of the invention fits closely to the trumpet T, the airsqueezed out by the constriction of the trumpet is expelled into thethroat region of the horn. Such air, as shown by the arrows in Figs. 2and 3, then moves in a direction. counter-current to the direction ofmovement of thersliveralongthe passageway formed by bulge 30 above thesliver, and is absorbed into the expanding fiber in the region of themouth portion of the horn enclo-. sure; This in effect provides a closedcircuit for. the air, and little can either escape or enter theenclosure,.

so that not only is the but any fly generated during its pasage islargely reabsorbed by the sliver. The result is that little fly iproduced around the output end of the drawing frame and any externaldust, dirt, lint or fly is kept from the sliver, resulting in a cleanerdrawing operation to provide superior yarn and cloth.

Various modifications of the invention within thespirit thereof and thescope of. the appended claims will be apparent to those skilled in thisart.

I claim:

1. In combination with a drawing frame having a pair of drafting elementoutput rolls followed by a pair of calender rolls having an inputtrumpet for feeding drafted sliver to a take-up package, a slivercontrolling enclosure for a web of sliver extending from adjacent thenip of said output rolls to adjacent said trumpet, said enclosure beingin the shape of a horn havinga narrow generally rectangular mouthopening of greater width than height positioned closely adjacent thenipv of said output rolls and a throat opening positioned closelyadjacent and above said trumpet, the bottom of said horn extendingcontinuously from adjacent said output roll nip to said trumpet and thetop of said horn joined with said bottom to provide enclosed sides:along the length of said horn, with the top of said i being bulgedupwardly being horn in the region of said throat for asubstantialdistance but of decreasing height toward said mouth openingto provide adjacent said mouth opening,

it expands beyond the nip of said output rolls.

2.. In combination with a drawing frame having a pair of draftingelement output'rolls followed by a pair of I calender rolls having aninput trumpet for feeding drafted sliver to a take-up package, a slivercontrolling enclosure for a web of sliver extending from adjacent thenip-z of said output rolls to adjacent said trumpet, said enclosurebeing in the shape of a generally flat bottomed. horn withflaring sidesand having a narrow generallyni rectangular-mouthopening of greaterwidth than height: positioned closely adjacent the nip of said outputrolls. r and a throat opening of generally semi-circular *con figurationpositioned closely adjacent and above said trumpet-incontact with theface of said trumpet then generally flat. bottom ofsaid horn extendingcontinu-p ously from adjacent said output roll-nip tozsaid trumpet" andhaving an interior surface of non-static electricity; horn being joinedwith-said bottom to provide flared enclosed sides: along with the top ofsaid horn-in;

generating material, and the top. of said sliver as it expands beyondthe nip of said output rolls.

3. In combination with a drawing frame having a.-

pair of drafting element output rolls followed by a pair.

of calender; rolls having an input trumpet for. feedingsliver to a takeup package,.a sliver controlling.,. enclosure fora web ofsliverextending from adjacent, the nip of: said output rolls to .adjacent saidtrumpet rolls, said enclosure being in the shape of a horn having.

drafted a sheetzmetal generally fiat-bottomed floor portion withinturned flaring sides and a transparent plastic cover i portion withinturned flaring sides and a transparent plastic cover .portion having afiange'resting on said in-'- turned sides, said. portions togetherprovidingsaid horn withxa narrow generally rectangular mouth opening,of.v greater width than height positioned closely adjacent .the

opening 'of gen-.- erally semi-circular configuration positioned closely-adnip..of .saidoutput rolls. and a throat.

sliver conveyed without damage, 7

a substantially flat top whereby air expressed from,-v saidsliverby-said trumpet moves along said bulge toward.

said; mouthopening ;for reabsorption into the sliver .as-

provide a substantially flat top,

trumpet moves along said bulges toward said mouth opening forreabsorption into the:

distance but of decreasing height toward said mouth 10 opening toprovide a substantially flat top adjacent said mouth opening, wherebyair expressed from said sliver by said trumpet rolls moves along saidbulge toward said mouth opening for absorption into the sliver as it 5expands beyond the nip of said output rolls.

References Cited in the file of this patent FOREIGN PATENTS 587,095Great Britain Apr. 14, 1947

